Help with Corsair Vengeance 1866mhz Dual Channel

birty1992

birty1992

birty1992

Associate
Joined
23 Jan 2012
Posts
20
Hey guys, this is the product i have : http://www.overclockers.co.uk/showproduct.php?prodid=MY-292-CS&tool=3

And im running it in the Asus Maximus IV Extreme-Z, I know this board supports all the way upto 2133mhz memory,

However When i did some checks in CPU-Z it seems they are being downclocked to 1333mhz which i thought was just because the frequency is set to auto in the bios, it seems when i enter my bios and change the Memory frequency from Auto to 1866mhz and then save and reboot, i can get into my OS and maybe 1-2 minutes in i get a blue screen, Can anyone help me understand why my memory is doing this? I can post more details if you need them, thanks again :)

P.S. i noticed these words on the memory product page:

- Tested together at 1866MHz, Vdimm = 1.50V, at latency settings of 9-9-9-24 on Intel DDR3-based motherboards.
- SPD programmed at: JEDEC standard 9-10-9-27 values at 1333MHz.

Does this have anything to do with it?

In the meantime im going to go and try and find this XMP thing in my bios see what that does :)
 
Last edited:
xmp is in the bios,it sets the ram speed/timings/voltages for you, if you manually set them then you need more vccio voltage with 1866mhz anywhere between 1.1v to 1.2v max,no higher idealy around 1.1v to 1.15v depending on your cpu's memory controller
 
Im using this ram with an Asus M5a97 PRO - I cant see an xmp setting in the bios, only manual up to 1600MHz....any ideas how I get it up to 1866?
Thanks
 
darrenbe said:
Im using this ram with an Asus M5a97 PRO - I cant see an xmp setting in the bios, only manual up to 1600MHz....any ideas how I get it up to 1866?
Thanks
Click to expand...

The motherboard doesn't support XMP profiles as it's an Intel thing.

All, or at least the vast majority, of AMD boards don't support it.

The highest frequency allowed in the BIOS is 1600MHz.

To run at 1866MHz you'll have to overclock the Bus Speed (or whatever it's called) by 16.625% (1866/1600).

This in turn will overclock the processor as well, unless you reduce the multiplier, so you'll have to get it all working nicely together.
 
Thanks for the info.

The mb has a smart overclock feature which has oc'd my 1100T to 3.8GHz by upping the fsb speed, not the multiplier, which is interesting....but good...

I can get the memory running at just under 1600 again my modidfying the memeory speed setting in the bios but it has a hissy fit if I try to run it at 1866.

So was there any point in me paying a premium for 1866 memory, when I could have got away with 1600?

I just went for the fastest dual channel ddr3 stuff that I thought was a reasonable price.....the sales person at OCuk just said it will work with the mb okay, and that was my main concern....

cheers.
 
darrenbe said:
Some screen grabs of cpu tabs:

Cheers.
Click to expand...

First the explanation.

Your RAM is currently running at 1551.8MHz (775.9 x 2 as it's Double Data Rate).

The speeds shown in the BIOS are based on the standard Bus Speed of 200MHz.

If the system wasn't overclocked then your RAM would be running at 1333MHz.

(200MHz x 10/3 x 2 for DDR) = 1333MHz

As it is it's running at 1551.8MHz.

(232.8MHz x 10/3 x 2 for DDR) = 1551.8MHz

Effectively your current RAM speed is based on the 1333MHz setting.

Now if you change the RAM speed in the BIOS to 1600MHz you would get this with a standard 200MHz bus speed:

(200MHz x 4 x 2 for DDR) = 1600MHz

As the bus speed is overclocked to 232.8MHz then using the 1600MHz setting in the BIOS will give:

(232.8MHz x 4 x 2 for DDR) = 1862.4MHz

------------------------------------------------------------------------------------------------------------------------------------------------------

Now the how to bit.

Before proceeding save your current settings to a profile under the Tool menu in the BIOS so you can load them again if it all goes pear shaped.

Based on the SPD settings then to get your RAM running as close to 1866MHz as you can get do the following in the BIOS:

1) In the Ai Tweaker menu set the Memory Frequency to 1600MHz

2) In the Ai Tweaker menu set the DRAM Voltage to 1.5V

3) In the DRAM Timing Control sub menu set:

  • DRAM CAS# Latency to 9
  • DRAM RAS# to CAS# Delay to 10
  • DRAM RAS# PRE Time to 9
  • DRAM RAS# ACT Time to 27
  • DRAM Command Rate to 2T
Save the changes and, hopefully, you'll be running as close to 1866MHz as you can.
 
Last edited:
Looks good, got it running at 1856......many thanks.

Now the question is, ultimately what diff will it make....and should I run something like burn-in tests to make sure it's stable?
 
You're welcome.

Ultimately it isn't going to make a massive difference to the performance of your PC but at least you're getting what you paid for.

If you want to test for stability then just try some demanding applications. Play a game, encode some video or whatever you do on the PC.

You'll soon find out if it's not stable.
 
You must log in or register to reply here.
Back
Top Bottom